======Fragile X Syndrome ======
====Main Features====
  * Intellectual disability (most common cause of inherited disability)
  * Global developmental delay
  * Autism

====Eye Findings====
  * Refractive Error (17%)
    * Myopia
    * Astigmatism
  * Strabismus (8%)
    * Esotropia
  * Nystagmus- rare
====Other Findings====
  * Long narrow face
  * Prominent ears
  * Macroorchidism after puberty
  * Joint hypermobility
  * Mitral valve prolapse 
  * Aortic Root dilation
  * Seizures (15% males and 5% females
====Etiology====
  * mutation in FMR1 gene on Xq27.3
    * results in hypermethylation and no gene product
    * Gene product- fragile X messenger ribonucleoprotein- protein involved in synapse development and neuronal function
====Resources====
  * {{::ocular_status_of_boys_with_fragile_x_syndrome.pdf |Hatton DD et al. Ocular status of boys with fragile X syndrome: a prospective study. JAAPOS 1998;2(5):298-302}}
  * [[https://pubmed.ncbi.nlm.nih.gov/28960184/|Pubmed Abstract: Hagerman RJ. et al. Fragile X Syndrome. Nat Rev Dis Primers. 2017;29:3:17065]]


{{tag>syndrome}}